Screw-propeller



(No Model.) 2 Sheets-Sheet 1. M. N. BRAY.

SCREW PROPBLLBR.

N0. 554,331. Patented Feb. 11, 1896.

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2 Sheets-Sheet 2. M. N. BRAY. V SCREW PROPELLER.

Patented Feb. 1]., 1896.

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' ,tion on line 3 3 on .tion of one of the propeller-blades detached are respectively a side elevation and an end UNITED STATE PATENT OFFICE.

MELLEN N. BRAY, or BOSTON, MASSACHUSETTS.

SCREW-PROPELLER.

SPECIFICATION forming part of Letters Patent N 0. 554,331, dated February 11, 1896. Application filed June 27,1895. Sefia1No.554,264 (No model.)

To all whom it may concern:

Be it known that I, MELLEN N. BRAY, of

Boston, in the county of Sufiolk and State of features of construction, arrangement, and

combination of parts which will be best understood by reference to the description of the accompanying drawings and to the claims hereto appended, and in which my inyention is clearly pointed out.

Figure 1 0f the drawings is a plan of a screwpropeller, illustrating my invention. Fig. 2 is a side elevation of the same with a portion of the propeller-hub cut in section on line 1 1 on Figs. 1 and 3. Fig. 3 is a sectional elevation, the cutting-plane being through propeller-shaft on line 2 on Fig. 2. Fig. 4 is a sec-- ig. 2. Fig. .5 is an elevafrom its hub. Fig. 6 is an end view of. said blade. Fig. 7 is a plan of the propeller-hub with the blades and the journal-caps removed. Fig. 8'is an elevation of the outer-lend face of the same. Fig. 9 is asection on'gline 4 4 on Fig. 8. Figs. 10, 1'1, and 12 are respectively a plan, a rear elevation, and an end view of the cap of the journal-box. Fig. 13'is a side elevation of the reversing-hub and portions of lows: The blades of the propeller being set the crank-engaging bars. Fig. 14. is a transverse section on line 5-5-on Fig. 13, looking toward the left of said figure. Figs. 15 and 16 elevation of the shipper-yoke, and Figs. 1 7 and 18 are respectivelyan elevation and an edge view of the crank-pin block. V Y

-,,In the drawings, A is the propeller-shaft having a portion of its lengthnea'r its rearend made tapering to receive the hub B, having a correspondingly-tapered central bore, and secured upon said shaftby the clamping-tints and the check nuta fitted to the threaded end portion of said shaft, as shown'in Fig. 4.

The hub B has formed integral therewith the two laterally-projecting half-boxes B, to which are bolted the caps B to form two journal-boxes in which are mounted the journals C'of the propeller-blades O, as shown in Figs. 1 and 2. Each of thejournals C of the blades 0 has formed upon its inner end a crank I) provided with a crank-pin 1), upon which is fitted the rectangular block 0, said cranks being inclosed in the chambers d d formed .in the hub B and movable about the axes of said journals 0 a-distance equal to about forty degrees, more or less, to vary the pitch of the blades 0 or to reverse their angular positions relative to a plane cuttingthrough their axes at right angles to the axis of the propellershaft.

The inner end of the hub B has formed therein a cylindrical chamber 13 to receive the reversing-hub D, which is fitted upon the shaft A so as to be movable endwise thereof and revoluble therewith and has secured thereto the two rearwardly-projecting arms D D, which are fitted to'suitable hearings in the hub B and are provided near their rear .ends with rectangular notches to engage the blocks 0 c mounted on said crank-pins b, as shown in Fig. 2.

-The reversing-hub D has formed thereon the annular grooved, to which is fitted the shipping-yoke E, provided with the two opposite trunnions e, which are to be engaged by any suitable shipper leveror rod (not shown) arranged to move said yoke and hub to and fro parallel with the axis of the shaft without interfering with the revolution of the said shaft and the propeller.

The operation of my invention is as folas shown inthe drawings, thefshaft A is revolved. in the direction indicated by the arrow on Fig. 3, when the boat will be driven ahead. If it is desired to check the speed of theboat and move it astern suddenly the engineer moves the yoke E and the hub D toward the rear, when the angles of the blades 0 will'be reversed, and without stopping or reversing the rotation of the shaft A the motion of the boat will-be reversed. This is a great advantage, particularly in small boats the engines of which are not provided I withreversing-gears. As thehub D fits the cylindrical chamber B closely the wall of said chamber is provided with vent-holes ff for the escape of Water from said chamber when said hub is moved into the same.

What I claim as new, and desire to'secure by Letters Patent of the United States, is 1. In a screw-propeller, the combination of an operating-shaft: a hub secured to said shaft in a fixed position and provided with a plurality of journal-boxes to receive the journals of the propeller-blades, and with a plu rality of longitudinal guideways arranged eccentric to the axis of revolution of said hub: a plurality of blades revolubly mounted in said journal-boxes: a crank formed upon, or secured to, the inner end of each of the journals of said blades: a hub fitted upon,

revoluble with, and movable endwise of said operating-shaft, and provided with a circumferential groove: a plurality of bars fitted to said longitudinal guideways so as to be supported thereby, and movable endwise therein, and firmly secured at one end to said endwise-movable hub, and provided, at their other ends, with rectangular transverse notches or longitudinal guideways eccentric to its axis of revolution; the blades 0 provided with the journals 0'; the cranks b; crank-pins b; the

blocks a c fitted to said crank-pins; the hub 7D provided with the circumferential groove (1; the shipping-yoke E and the arms D fitted to and supported by said guideways, and connecting said hub D to the cranks b all constructed and operating substantially as described. a 4 I In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this 2-tth day of June, A. D. 1895.

MELLEN N. BRAY' Witnesses:

N. O. LOMBARD, M E. CRocKER; 

